VERSA-LOK® Retaining Wall Systems has been creating Solid Solutions™ for architects, engineers, contractors and homeowners since 1987. The company pioneered the solid, pinned segmental retaining wall ( SRW ) system and holds numerous patents for the top-down, hole-to-slot pinning system. Imitated but never duplicated, VERSA-LOK is well known among landscape architects, specifiers, contractors and homeowners for ease of installation and design flexibility.